Features:
★ Easy to Operate: Just place it on a cup of hot water, and gently flip the wheel until the wheel can run automatically.
★ Superior Performance: By operating the engine, children would observe and know the operational process and more intuitive understanding of the operating principle of Stirling engine, deepening interest in physics. 
★ A Stirling Engine Model: Made of premium metal, and the high intensity PC material is and . Transparent body gives you a clear view on how every parts work.
★ for Children: No need to fire an lamp, safer for children. Fully assembled, no need to install it yourself. 
★ Educational Toy: classroom or laboratory experimental teaching aids, the choice gift for students, teachers, children, friends and colleagues.

Specification:
Model: D3
Material: Metal,PC
Size: 9.9 x 11.4cm(DxH)
Weight: 218g/7.7oz
Package Size: 19 x 10.8 x 13/7.5 x 4.2 x 5.1in
Package Weight: 343g/12.1oz

Specification:
1 x Stirling Engine Model